Portable power tool, battery pack, and cell configurations for same

ABSTRACT

Various battery packs are presented for use with twenty volt (20 V) power tools. In some embodiments, one or more lithium-ion battery cells of the battery packs are received by a handle of the power tool.

FIELD OF THE INVENTION

Various embodiments relate to power tools and battery packs, and moreparticularly, to twenty volt, lithium ion battery packs and the portablepower tools that use them.

BACKGROUND OF THE INVENTION

Lithium ion battery packs for power tools include several cylindrical,lithium ion battery cells. Each cylindrical cell typically produces3.6-4.0 volts. More specifically, such cells typically provide 3.6 voltsduring use and 4.0 volts when fully charged. Marketing departments maylabel battery packs using such lithium ion cells with voltages between3.6-4.0 volts or multiples thereof depending on the number of cells inseries. Lithium ion battery packs for portable power tools typicallyinclude either three lithium ion cells or five lithium ion cells (ormultiples thereof in parallel). The three cell packs generally provide10.8-12.0 volts and are commonly referred to as 12 volt packs. The fivecell packs generally provide 18-20 volts are commonly referred to as 20volt packs. Power tools using the 12 volt packs have the advantage ofbeing lighter and more compact. Conversely, power tools using the 20volt packs are more powerful.

Limitations and disadvantages of conventional and traditional approachesshould become apparent to one of skill in the art, through comparison ofsuch systems with aspects of the present invention as set forth in theremainder of the present application.

BRIEF SUMMARY OF THE INVENTION

Power tools and various lithium ion battery packs for such power toolsare substantially shown in and/or described in connection with at leastone of the figures, and are set forth more completely in the claims.

These and other advantages, aspects and novel features of the presentinvention, as well as details of an illustrated embodiment thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1A-1C show a power tool system that includes a power tool, abattery pack, and battery charger in accordance with an embodiment ofthe present invention.

FIGS. 2A-2D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 3A-3D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 4A-4D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 5A-5D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 6A-6D show a power tool system that includes a power tool and abattery back in accordance with an embodiment of the present invention.

FIGS. 7A-7D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 8A-8D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 9A-9D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 10A-10D show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 11A-11E show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 12A-12C show a power tool system that includes a power tool and abattery pack in accordance with an embodiment of the present invention.

FIGS. 13A and 13B show battery cell arrangements in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the present invention are related to power tools and batterypacks used by such tools. More specifically, certain embodiments of thepresent invention relate to power tools that may use battery packshaving a variety of different forms, cell configurations, and powercapabilities. Thus, a power tool vendor may provide a variety ofdifferent battery packs in order to permit greater flexibility inmatching power, size, weight, etc. of the battery pack to the job athand. For some jobs, a customer may desire or need greater power. Forother jobs, the customer may be willing to sacrifice some power orbattery life in order to have a smaller, lighter, better balanced,and/or maneuverable power tool.

The figures of the present application generally depict a power tool inthe form of a drill driver. Such depiction of a drill driver is forillustrative purposes. The various disclosed battery packs and cellconfigurations may be utilized with other types of power tools such as,for example impact wrenches, circular saw, miter saws, impact drivers,etc. to name a few.

FIGS. 1A and 1B shows a power tool system comprising a power tool 10 anda battery pack 20. In particular, FIG. 1A depicts the battery pack 20attached to the power tool 10 and FIG. 1B depicts the battery pack 20detached from the power tool 10. FIG. 1C further shows a charger 50 ofthe power tool system, which may be used to recharge battery cells ofthe battery pack 20.

As shown in FIGS. 1A and 1B, the power tool 10 may include a handle 11providing a battery compartment configured to receive the battery pack20. More specifically, the handle 11 may include a cavity 12 configuredto receive a post portion 22 of the battery pack 20. The post portion 22may be inserted into a proximal end of the cavity 12. The post portion22 may slide longitudinally into the cavity 12 of the handle 11 andtoward a distal end of the cavity 12 until properly seated and attachedto power tool 10.

The post portion 22 may include electrical contacts (not shown) that areconfigured to electrically couple to electrical contacts of the powertool 10 when the post portion 22 is inserted and seated in the cavity12. In particular, electrical contacts of the power tool 10 and batterypack 20 may electrically couple rechargeable, battery cells of thebattery pack 20 to components (e.g., motor, controller, etc.) of thepower tool 10 so as to provide such components with electrical powerwhen the battery pack 20 is attached to the power tool 10.

The battery pack 20 may further include locking or latching deviceswhich are configured to mechanically, and selectively couple or latchthe battery pack 20 to the power tool 10. In particular, left and rightsides of the base portion 24 may each include spring-loaded detents andcorresponding release buttons. The detents may engage correspondingrecesses or catches of the power tool 10 and secure the battery pack 20to the power tool 10. When pressed, the release buttons may actuatecorrespond detents and cause such detents to disengage the recesses,thus permitting the battery pack 20 to be disengaged and removed fromthe power tool 10.

FIG. 1C depicts a battery charger 50 with a cavity 52 configured toreceive the post portion 22 of the battery pack 20. The battery charger50 is configured to charge the one or more rechargeable, battery cellsof the battery pack 20 when the post portion 22 is inserted in cavity 52and the post battery 20 is properly seated in the battery charger 50.The battery charger 50 may include electrical contacts (not shown) thatengage the electrical contacts of the battery pack 20 when the postportion 22 is properly inserted and seated in the cavity 52. In thismanner, the battery charger 50 may supply the one or more rechargeable,battery cells with electrical power used to recharge such cells.

As shown in FIG. 1A, the battery pack 20 may include an outer housing orcasing that comprises the post portion 22 and a base or boot portion 24.The post portion 22 and base portion 24 generally house a plurality ofcylindrical, lithium ion battery cells that supply power to the powertool 10 during use. As explained in more detail below, the post portion22 in various embodiments may include one or more battery cells. Due tohousing one or more battery cells in the post portion 22, all or atleast a portion of such cells are positioned within the handle 11 of thepower tool 10 when the battery pack 20 is attached to the power tool 10.Such a configuration reduces the size of the base portion 24 incomparison to a configuration in which all battery cells of the batterypack are housed within the base portion 24. Moreover, by positioning oneor more battery cells in the post portion 22, the overall size orfootprint of the power tool 10 with attached battery pack 20 is alsoreduced since the portion of the battery pack 20 extending from thepower tool 10 (e.g., the base portion 24) is smaller. Accordingly, sucha power tool 10 with attached battery pack 20 may be easier to maneuverand use than a power tool in which the battery cells are housed solelyin a base portion of the attached battery pack.

Referring now to FIGS. 2A-2D, 3A-3D, and 4A-4D, an example power tool100 is shown in relation to three different twenty volt (20 V) batterypacks 200, 300, 400. More specifically, the 20 V battery pack 200 ofFIGS. 2A-2D includes five cylindrical, lithium ion batteries 210 havinga diameter of fourteen millimeters (14 mm). The 20 V battery pack 300 ofFIGS. 3A-3D includes five cylindrical, lithium ion batteries 310 havinga diameter of eighteen millimeters (18 mm). The 20 V battery pack 400 ofFIGS. 4A-4D includes five cylindrical, lithium ion batteries 310 havinga diameter of twenty millimeters (20 mm) to twenty-one millimeters (21mm), hereinafter referred to as 20 mm cells.

In comparison to the 18 mm cells 310 and 20 mm cells 410, the 14 mmcells 210 are compact and light. As such, battery pack 200 is smallerand lighter than the 18 mm cell, battery pack 300 and the 20 mm cell,battery pack 400. The 14 mm cells 210, however, are not as powerful asthe 18 mm cells 310 or the 20 mm cells. As such, the 14 mm battery pack200 is generally suitable for jobs where lighter weight, greatermaneuverability, and/or smaller size are preferred over greater powerand/or longer battery life.

The 20 mm cells 410 are larger and heavier than the 14 mm cells 210 andthe 18 mm cells 310. However, as a result of the larger size and greaterweight, the 20 mm cells 410 also provide more power than the 14 mm cells210 and the 18 mm cells 310. As such, the 20 mm cell, battery pack 400is generally better suited for jobs where greater power and/or longerbattery life is more important than size or weight.

The 18 mm cells 310 generally have a lower price point than either the14 mm cells 210 and the 20 mm cells 410 due to 18 mm cells 310 beingextremely prevalent resulting in a much higher manufacturing volume thanthe 14 mm cells 210 or the 20 mm cells 410. The 18 mm cells 310generally provide a performance level between the 14 mm cells 210 andthe 20 mm cells 410.

The power tool system of FIGS. 2A-2D, 3A-3D, and 4A-4D includes a powertool 100 configured to receive and use any of the battery packs 200,300, 400. In one embodiment, the battery packs 200, 300, 400 eachprovide a similarly sized and shaped post portion 220, 320, 420 forinsertion into the handle 110 of the power tool 100. However, in otherembodiments, each of the battery packs 200, 300, 400 may have adifferent shape and/or size and a battery compartment of the power tool100 may be configured to adapt to and/or operably receive each of thedifferent shaped/sized post portions 220, 320, 420. Regardless, thepower tool 100, due to its compatibility with each of the battery packs200, 300, 400, may enjoy the unique, benefits provided by each cellsize. For example, the power tool 100 may use the smaller, lighterweight battery pack 200 for light duty jobs, use the larger, heavier,and generally more expensive battery pack 400 for heavy duty jobs, andmay use the cheaper, all-purpose battery pack 300 when neither lightweight nor more power are paramount.

Referring now to FIGS. 2A-2D, further details of the battery pack 200with respect to power tool 100 will be explained. As shown, the batterypack 200 includes an outer housing 202 or casing having a post portion220 and a base portion 230. Similar to the power tool 10 of FIGS. 1A and1B, the power tool 100 may include a handle 110 providing a batterycompartment configured to receive the battery pack 200. Morespecifically, the handle 110 may include a cavity configured to receivethe post portion 220 of the battery pack 200. The post portion 220 maybe inserted and slid into a proximal end of the cavity toward a distalend of the cavity until the battery pack 200 is properly seated andattached to power tool 100.

The post portion 220 may include electrical contacts (not shown) thatare configured to electrically couple to electrical contacts of thepower tool 100 when the post portion 220 is inserted and seated in thehandle 110 of the power tool 100. In particular, electrical contacts ofthe power tool 100 and battery pack 200 may electrically couplerechargeable, battery cells 210 of the battery pack 200 to the powertool 100 so as to provide electrical power to electrical components ofthe power tool 100.

As shown in FIGS. 2C and 2D, the battery pack 200 includes five batterycells 210 in the housing 202. In particular, each battery cell 210 maynominally provide 4 volts and may be coupled in series with one anotherto realize a battery pack 200 that provides a nominal voltage of 20volts. The battery cells 210 may be any rechargeable battery cellchemistry type, such as, for example, nickel cadmium (NiCd),nickel-metal hydride (NiMH), Lithium (Li), Lithium-ion (Li-ion), otherLithium-based chemistry, other rechargeable battery cell chemistry, etc.However, in one preferred embodiment, each of the battery cells 210 is alithium-ion battery cell.

As shown, each battery cell 210 may have generally cylindrical shape andmay extend along a cell axis 242, 252 that is parallel to an outer,cylindrical cell wall of each cell 210. Moreover, each battery cell 210may have a diameter of about fourteen millimeters (14 mm) and a lengthin the range of about sixty millimeters (60 mm) to about seventymillimeters (70 mm), with nominal lengths of 60 mm, 65 mm, and 70 mmpreferred in some embodiments.

As shown, the battery cells 210 are arranged in a first group 240 ofthree battery cells and a second group 250 of two battery cells. In thefirst group 240, the cell axes 242 are parallel to one another. In thesecond group 250, the cell axes 252 are parallel to each other. However,the first group 240 and the second group 250 are arranged so that thecell axes 242 of the first group 240 are not parallel to the cell axes252 of the second group 250. As shown in FIG. 2D, the cell axes 242 ofthe first group 240 may be perpendicular or nearly perpendicular (e.g.,90°±5°) to the cell axes 252 of the second group 252. However, in otherembodiment, the cell axes 242 of the first group 240 may form a moreacute angle (e.g., between about 90° and about 70°, or between about 90°and about 45°) with the cell axes 252 of the second group 250.

Moreover, the first group 240 of cells 210 are positioned to correspondto the post portion 220 of the battery pack housing 202 and the secondgroup 250 of cells 210 are positioned to correspond to the base portion230 of the battery pack housing 202. As a result of such configuration,the first group 240 of cells 210 are generally received by the handle110 of the power tool 100 when the battery pack 200 is attached to thepower tool 100. Conversely, the second group 250 of cells 210 aregenerally not received by the handle 110 of the power tool 100 when thebattery pack 200 is attached to the power tool.

In some embodiments, the first group 240 of cells 210 are completelyreceived by the power tool 100 or handle 110 such that 100% of thevolume of each cell 210 in the first group 240 is contained within thepower tool 100 or handle 110. In other embodiments, the first group 240is substantially received by the handle 110 such that greater than 80%of the volume of each cell 210 is contained within the power tool 100 orhandle 110 and less the 20% of the volume of each cell 210 extendsbeyond the power tool 100 or handle 110. In yet other embodiments, thefirst group 240 is mostly received by the power tool 100 or handle 110such that greater than 50% of the volume of each cell 210 is containedwithin the power tool 100 or handle 110 and less the 50% of the volumeof each cell 210 extends beyond the power tool 100 or handle 110.

By arranging the battery cells 210 in the battery pack 200 such that oneor more cells 210 extend into the power tool 100 or handle 110 whenattached, the battery pack 200 reduces the overall size or footprint ofthe power tool 100 when in use. More specifically, a battery pack suchas battery pack 200 reduces the usable footprint of the power tool 100when compared to a battery pack in which none of the cells arecontained, substantially contained, or mostly contained by the powertool 100 or handle 110 when the battery pack is attached to the powertool 100.

Referring now to FIGS. 3A-3D, further details of the battery pack 300with respect to power tool 100 will be explained. As shown, the batterypack 300 includes an outer housing 302 or casing having a post portion320 and a base portion 330. Similar to the post portion 220 of batterypack 200, the post portion 320 may be inserted and slid into a proximalend of a power tool cavity toward a distal end of the cavity until thebattery pack 300 is properly seated and attached to power tool 100.

The post portion 320 may include electrical contacts (not shown) thatare configured to electrically couple to electrical contacts of thepower tool 100 when the post portion 320 is inserted and seated in thehandle 110 of the power tool 100. In particular, electrical contacts ofthe power tool 100 and battery pack 300 may electrically couplerechargeable, battery cells 310 of the battery pack 300 to the powertool 100 so as to provide electrical power to electrical components ofthe power tool 100.

As shown in FIGS. 3C and 3D, the battery pack 300 includes five batterycells 310 in the housing 302. In particular, each battery cell 310 maynominally provide 4 volts and may be coupled in series with one anotherto realize a battery pack 300 that provides a nominal voltage of 20volts. The battery cells 310 may be any rechargeable battery cellchemistry type, such as, for example, nickel cadmium (NiCd),nickel-metal hydride (NiMH), Lithium (Li), Lithium-ion (Li-ion), otherLithium-based chemistry, other rechargeable battery cell chemistry, etc.However, in one preferred embodiment, each of the battery cells 310 is alithium-ion battery cell.

As shown, each battery cell 310 may have generally cylindrical shape andmay extend along a cell axis 342, 352 that is parallel to an outer,cylindrical cell wall of each cell 310. Moreover, each battery cell 310may have a diameter of about eighteen millimeters (18 mm) and a lengthin the range of about sixty millimeters (60 mm) to about seventymillimeters (70 mm), with nominal lengths of 60 mm, 65 mm, and 70 mmpreferred in some embodiments.

As shown, the battery cells 310 are arranged in a first group 340 of twobattery cells and a second group 350 of three battery cells. In thefirst group 340, the cell axes 342 are parallel to one another. In thesecond group 350, the cell axes 352 are parallel to each other. However,the first group 340 and the second group 350 are arranged so that thecell axes 342 of the first group 340 are not parallel to the cell axes352 of the second group 350. As shown in FIG. 3D, the cell axes 342 ofthe first group 340 may be perpendicular or nearly perpendicular (e.g.,90°±5°) to the cell axes 352 of the second group 352. However, in otherembodiments, the cell axes 342 of the first group 340 may form a moreacute angle (e.g., between about 90° and about 70°, or between about 90°and about 45°) with the cell axes 352 of the second group 350.

Moreover, the first group 340 of cells 310 are positioned to correspondto the post portion 320 of the battery pack housing 302 and the secondgroup 350 of cells 310 are positioned to correspond to the base portion330 of the battery pack housing 302. As a result of such configuration,the first group 340 of cells 310 are generally received by the handle110 of the power tool 100 when the battery pack 300 is attached to thepower tool 100. Conversely, the second group 350 of cells 310 aregenerally not received by the handle 110 of the power tool 100 when thebattery pack 300 is attached to the power tool.

In some embodiments, the first group 340 of cells 310 are completelyreceived by the power tool 100 or handle 110 such that 100% of thevolume of each cell 310 in the first group 340 is contained within thepower tool 100 or handle 110. In other embodiments, the first group 340is substantially received by the handle 110 such that greater than 80%of the volume of each cell 310 is contained within the power tool 100 orhandle 110 and less the 20% of the volume of each cell 310 extendsbeyond the power tool 100 or handle 110. In yet other embodiments, thefirst group 340 is mostly received by the power tool 100 or handle 110such that greater than 50% of the volume of each cell 310 is containedwithin the power tool 100 or handle 110 and less the 50% of the volumeof each cell 310 extends beyond the power tool 100 or handle 110.

By arranging the battery cells 310 in the battery pack 300 such that oneor more cells 310 extend into the power tool 100 or handle 110 whenattached, the battery pack 300 reduces the overall size or footprint ofthe power tool 100 when in use. More specifically, a battery pack suchas battery pack 300 reduces the usable footprint of the power tool 100when compared to a battery pack in which none of the cells arecontained, substantially contained, or mostly contained by the powertool 100 or handle 110 when the battery pack is attached to the powertool 100.

Referring now to FIGS. 4A-4D, further details of the battery pack 400with respect to power tool 100 will be explained. As shown, the batterypack 400 includes an outer housing 402 or casing having a post portion420 and a base portion 430. Similar to the post portion 220 of batterypack 200, the post portion 420 may be inserted and slid into a proximalend of a power tool cavity toward a distal end of the cavity until thebattery pack 400 is properly seated and attached to power tool 100.

The post portion 420 may include electrical contacts (not shown) thatare configured to electrically couple to electrical contacts of thepower tool 100 when the post portion 420 is inserted and seated in thehandle 110 of the power tool 100. In particular, electrical contacts ofthe power tool 100 and battery pack 400 may electrically couplerechargeable, battery cells 410 of the battery pack 400 to the powertool 100 so as to provide electrical power to electrical components ofthe power tool 100.

As shown in FIGS. 4C and 4D, the battery pack 400 includes five batterycells 410 in the housing 402. In particular, each battery cell 410 maynominally provide 4 volts and may be coupled in series with one anotherto realize a battery pack 400 that provides a nominal voltage of 20volts. The battery cells 410 may be any rechargeable battery cellchemistry type, such as, for example, nickel cadmium (NiCd),nickel-metal hydride (NiMH), Lithium (Li), Lithium-ion (Li-ion), otherLithium-based chemistry, other rechargeable battery cell chemistry, etc.However, in one preferred embodiment, each of the battery cells 410 is alithium-ion battery cell.

As shown, each battery cell 410 may have generally cylindrical shape andmay extend along a cell axis 442, 452 that is parallel to an outer,cylindrical cell wall of each cell 410. Moreover, each battery cell 410may have a diameter of about twenty millimeters (20 mm) and a length inthe range of about sixty millimeters (60 mm) to about seventymillimeters (70 mm), with nominal lengths of 60 mm, 65 mm, and 70 mmpreferred in some embodiments.

As shown, the battery cells 410 are arranged in a first group 440 of twobattery cells and a second group 450 of three battery cells. In thefirst group 440, the cell axes 442 are parallel to one another. In thesecond group 450, the cell axes 452 are parallel to each other. However,the first group 440 and the second group 450 are arranged so that thecell axes 442 of the first group 440 are not parallel to the cell axes452 of the second group 450. As shown in FIG. 4D, the cell axes 442 ofthe first group 440 may be perpendicular or nearly perpendicular (e.g.,90°±5°) to the cell axes 452 of the second group 452. However, in otherembodiments, the cell axes 442 of the first group 440 may form a moreacute angle (e.g., between about 90° and about 70°, or between about 90°and about 45°) with the cell axes 452 of the second group 450.

Moreover, the first group 440 of cells 410 are positioned to correspondto the post portion 420 of the battery pack housing 402 and the secondgroup 450 of cells 410 are positioned to correspond to the base portion430 of the battery pack housing 402. As a result of such configuration,the first group 440 of cells 410 are generally received by the handle110 of the power tool 100 when the battery pack 400 is attached to thepower tool 100. Conversely, the second group 450 of cells 410 aregenerally not received by the handle 110 of the power tool 100 when thebattery pack 400 is attached to the power tool.

In some embodiments, the first group 440 of cells 410 are completelyreceived by the power tool 100 or handle 110 such that 100% of thevolume of each cell 210 in the first group 240 is contained within thepower tool 100 or handle 110. In other embodiments, the first group 440is substantially received by the handle 110 such that greater than 80%of the volume of each cell 410 is contained within the power tool 100 orhandle 110 and less the 20% of the volume of each cell 410 extendsbeyond the power tool 100 or handle 110. In yet other embodiments, thefirst group 440 is mostly received by the power tool 100 or handle 110such that greater than 50% of the volume of each cell 410 is containedwithin the power tool 100 or handle 110 and less the 50% of the volumeof each cell 410 extends beyond the power tool 100 or handle 110.

By arranging the battery cells 410 in the battery pack 400 such that oneor more cells 410 extend into the power tool 100 or handle 110 whenattached, the battery pack 400 reduces the overall size or footprint ofthe power tool 100 when in use. More specifically, a battery pack suchas battery pack 400 reduces the usable footprint of the power tool 100when compared to a battery pack in which none of the cells arecontained, substantially contained, or mostly contained by the powertool 100 or handle 110 when the battery pack is attached to the powertool 100.

Referring now to FIGS. 5A-5D, further details of another power toolsystem comprising a power tool 100′ and a battery pack 500. The powertool system is similar to the power tool system of FIGS. 2A-2D, 3A-3D,and 4A-4D. However, the battery cells 510 of battery pack 500 arestacked in a longitudinal manner. Namely, the battery pack 500 likebattery packs 200, 300, 400 includes a first group 540 of battery cellsand a second group 550 of battery cells. However, the first group 540 isshown having a single battery cell 510 and the second group 550 is shownas having four battery cells 510. Moreover, the cells 510 of the firstgroup 540 are stacked longitudinally upon the cells 510 of the secondgroup 550 such that the cell axes 542, 552 of each group 540, 550 areparallel or nominally parallel (e.g., ±5°) to one another.

Moreover, the first group 540 of cells 510 are positioned to correspondto a post portion 520 of the battery pack housing 502 and the secondgroup 550 of cells 410 are positioned to primarily correspond to thebase portion 530 of the battery pack housing 502. However, as depicted,the second group 550 of cells 510 may significantly extend into the postportion 520 as well. As a result of such an arrangement, the first group540 of cells 510 are generally received by the handle 110 of the powertool 100 when the battery pack 400 is attached to the power tool 100.Moreover, at least a significant portion of the second group 450 ofcells 410 are also received by the handle 110 of the power tool 100 whenthe battery pack 400 is attached to the power tool.

In some embodiments, the first group 540 of cells 510 is completelyreceived by the power tool 100 or handle 110 such that 100% of thevolume of each cell 510 in the first group 540 is contained within thepower tool 100 or handle 110. Moreover, the second group 540 issignificantly received by the handle 110 such that greater than 20% ofthe volume of each cell 510 is contained within the power tool 100 orhandle 110. In yet other embodiments, the second group 550 is mostlyreceived by the power tool 100 or handle 110 such that greater than 50%of the volume of each cell 510 is contained within the power tool 100 orhandle 110 and less the 50% of the volume of each cell 510 of the secondgroup 550 extends beyond the power tool 100 or handle 110.

Referring now to FIGS. 6A-6D, further details of another power toolsystem comprising a power tool 100″ and a battery pack 600. The powertool system is similar to the power tool system of FIGS. 2A-2D, 3A-3D,and 4A-4D. However, the battery cells 610 in the base portion 630 arestacked like logs. Namely, the battery pack 600 like battery packs 200,300, 400 includes a first group 640 of battery cells and a second group550 of battery cells. However, the cells 610 of the second group 650 arestacked such that the cylindrical walls of at least one of the batterycells 610 rests upon the cylindrical walls or is positioned above thecylindrical walls of another battery cell 610 of the second group 650.

The first group 640 of cells 510 are positioned to correspond to a postportion 620 of the battery pack housing 602 and the second group 650 ofcells 610 are positioned to primarily correspond to the base portion 630of the battery pack housing 602. Similar to battery packs 200, 300, and400, the first group 640 of cells 410 may be completely received, may besubstantially received, or may be mostly received by the power tool 100or handle 110 such that 100%, greater than 80%, or greater than 50% ofthe volume of each cell 610 in the first group 640 is contained withinthe power tool 100 or handle 110.

Referring now to FIGS. 7A-7D, further details of another power toolsystem comprising a power tool 100′″ and a battery pack 700. The powertool system is similar to the power tool system of FIGS. 2A-2D, 3A-3D,and 4A-4D. However, the battery cells 710 in the base portion 730 arespread apart to permit battery cells in the post portion 720 to extendinto the base portion 730. Namely, the battery pack 700 like batterypacks 200, 300, 400 includes a first group 740 of battery cells and asecond group 750 of battery cells. However, two of the cells 710 a, 710b from the second group 750 are laterally separated from each other suchthat a gap 754 is formed between the cylindrical walls of the two cells710 a, 710 b while the cell axes 752 a, 752 b of the two cells 710 a,710 b remain parallel to each other. Furthermore, the third cell 710 cis positioned such that the cell axis 752 c of the third cell 710 c isperpendicular to, but lies in the same plane as the cell axes 752 a, 752b of the two cells 710 a, 710 b. Such an arrangement, permits distal endof the cells 710 d, 710 e of the first group 740 to extend into the gap754 between the cells 710 a, 710 b, thus reducing the overall height ofthe battery pack 700. Moreover, such an arrangement results in the cellaxes 742 d, 742 e being perpendicular or nearly perpendicular with thecell axes 752 a, 752 b, 752 c. In some embodiments, the cell axes 742 d,742 e may form a more acute angle with the cell axes 752 a, 752 b, 752c.

Referring now to FIGS. 8A-8D, further details of another 20 V batterypack 800 for use with the power tool system of FIGS. 2A-2D, 3A-3D, and4A-4D. Unlike the packs 200, 300, 400, the battery pack 800 includes tenbattery cells 810 instead five battery cells. In particular, the firstgroup 840 associated with the post portion 820 of the housing 802includes two battery cells 810, but the second group 850 associated withthe base portion 830 of the housing includes eight battery cells 810.The cell axes 842 of the first group 840 are perpendicular or nearlyperpendicular to the cell axes 852 of the second group 850. However, thecells 810 of the second group 850 are arranged such that a first layer856 of four cells 810 are stacked such that their cylindrical walls arein close proximity (e.g., about 0.030 inches apart) to the cylindricalwalls of a second layer 858 of cells 810. Moreover, the cell axes 852are rotated with respect to the cell axes of packs 200, 300, 400 suchthat the cell axes 852 align with a line extending from a left and rightside of the power tool 100 instead of aligning with a line extendingfrom a front and back side of the power tool 100.

FIGS. 8A-8D depict the battery pack 800 with ten battery cells 810.However, a similar technique may be utilized to extend the battery pack800 to other multiples of five such as fifteen battery cells. Forexample, a third layer of five battery cells 810 could be arranged undersecond layer 858.

FIGS. 9A-9D show that the battery packs 200, 300, 400, 500, 600, 700,800 may be implemented such that the packs may be inserted into thepower tool 100 in at least two orientations. However, embodiments thatpermit insertion of the battery packs in a greater number oforientations are envisioned and contemplated.

As shown in FIGS. 9A and 9B, the base or boot portion 930 of a batterypack 900 may extend further to a front of the power tool 100 than towarda back of the power tool 100. As such, the battery pack 900 in theorientation of FIGS. 9A and 9B presents more weight toward the front ofthe power tool 100 than the back of the power tool 100. As shown inFIGS. 9C and 9D, the battery pack 900 inserted into the power tool 100such that the pack 900 extends further toward the back of the power tool100 than the front of the power tool 100. Such an orientation may betterbalance the power tool 100 along the handle 110 making the power tool100 easier to use. Furthermore, such rotation adjusts the foot print orsilhouette of the power tool 100 during use. When used in tightquarters, reorienting the battery pack 900 may provide additionalclearance enabling the use of the power tool 900 in a small area thatmay not otherwise be accessible or may be more difficult to access ifthe battery pack 900 were not reoriented.

Referring now to FIGS. 10A-10D, another embodiment of a power toolsystem is shown in which a first portion 1012 of the handle 1010 for thepower tool 1000 is provided by the power tool 1000 and a second portion1014 of the handle 1010 is provided by the battery pack 1100. Thebattery pack 1100 may be implemented in a manner similar to thepreviously discussed battery packs. However, the housing 1102 of thebattery pack 1100 may incorporate the second portion 1014 of the handle1010 into the post portion 1120 of the battery pack 1100. The batterypack 1100 may enable the power tool 1000 to have a smaller handle 1010since the handle 1010 no longer needs to provide clearance for receivingthe post portion 1120 of the battery pack 1100. For example, in theembodiment of FIGS. 10A-10D, the handle 1010 may provide clearance forthe receipt of a front surface 1122 of the post portion. However, sincethe second portion 1014 is incorporated into the post portion 1122, thepost portion 1120 does not have a corresponding rear surface to bereceived, thus permitting the handle 1010 to be smaller than otherwisewould be permitted.

Referring now to FIGS. 11A-11E, another embodiment of a power toolsystem is shown in which two battery cells 1210 are incorporated intothe handle 1310 of the 20 V power tool 1300. As a result ofincorporating two battery cells 1210 into the handle 1310, the handle1310 does not need to receive a post portion from battery pack. As such,the handle 1310 may be implemented to be smaller than the handles 110 ofthe above-described power tool 100. As shown, the power tool 1300 mayinstead user a smaller battery pack 1200 which includes three batterycells 1210 having cell axes 1252 roughly perpendicular to cell axes 1242of the battery cells 1210 incorporated into the handle 1310.Furthermore, the battery pack 1200 may include a slide portion 1220which may engage rails 1330 of the power tool 1300.

Referring now to FIGS. 12A-12C, yet another embodiment of a power toolsystem similar to the power tool system of FIGS. 11A-11E is shown. Likethe power tool system of FIGS. 11A-11E, the 20 V power tool 1400 ofFIGS. 12A-12C may incorporate one or more battery cells (not shown) intoits handle 1410. The battery pack 1500 may include a slide portion 1520similar to the slide portion 1320 of battery pack 1300. However, unlikethe battery pack 1200 which utilizes three cylindrical, lithium-ionbattery cells 1210, the battery pack 1500 may include one or morelithium polymer battery cells 1510. In another embodiment, the lithiumpolymer battery cells 1510 may provide twenty volts on their own, thuspermitting embodiments without additional battery cells in the handle1410.

While the above battery packs were described as using battery cellshaving a single size (e.g., 14 mm, 18 mm, or 20 mm), some battery packsmay utilize battery cells of more than one size. Mixing battery cells ofdifferent sizes may reduce the volume of consumed by the battery cellsof the battery pack and may help provide a denser design. For example,the right side of FIG. 13A illustrates an arrangement of ten batterycells using a single size (e.g., 18 mm lithium-ion cells). The left sideof FIG. 13A presents a similar arrangement of ten battery cells bututilizes a mix of cell sizes (e.g., 20 mm and 14 mm lithium-ion cells).The arrangement of ten cells of the left side may be capable ofdelivering similar performance as the arrangement of ten cells on theright side. However, as depicted, the arrangement of ten cells on theleft side has a reduced vertical height in comparison to the ten cellson the right side.

FIG. 13B depicts yet another arrangement of ten cells of mixed sizes(e.g., 20 mm and 14 mm lithium-ion cells). Again, the arrangement of tencells shown in FIG. 13B may be capable of delivering similar performanceas the arrangements shown in FIG. 13A. However, the arrangement of FIG.13 consumes a smaller volume than either arrangement of FIG. 13A.

In some embodiments, the battery packs may include circuitry to monitorbattery characteristics, to provide voltage detection, to store batterycharacteristics, to display battery characteristics, to inform a user ofcertain battery characteristics, to suspend current within the batterypack, to detect temperature of the battery pack, battery cells, and thelike, to transfer heat from and/or within the battery pack, and toprovide balancing methods when an imbalance is detected within one ormore battery cells. In some embodiments, such circuitry may include avoltage detection circuit, a boosting circuit, a state of chargeindicator, and the like.

In some embodiments, the circuitry may also include processing circuitrysuch as a microprocessor or microcontroller. The processing circuitrymay monitor various battery pack parameters (e.g., battery pack presentstate of charge, battery cell present state of charge, battery packtemperature, battery cell temperature, and the like), may store variousbattery pack parameters and characteristics (including battery packnominal voltage, chemistry, and the like, in addition to theparameters), may control various electrical components, and maycommunicate with other electrical devices, such as, for example, a powertool, a battery charger, and the like. In some embodiments, theprocessing circuitry may monitor each battery cell's present state ofcharge and may identify when an imbalance occurs (e.g., the presentstate of charge for a battery cell exceeds the average cell state ofcharge by a certain amount or drops below the average cell state ofcharge by a certain amount). In some embodiments, the processingcircuitry may re-balance the cells when an imbalance has been detected.

Various embodiments of the invention have been described herein by wayof example and not by way of limitation in the accompanying figures. Forclarity of illustration, exemplary elements illustrated in the figuresmay not necessarily be drawn to scale. In this regard, for example, thedimensions of some of the elements may be exaggerated relative to otherelements to provide clarity. Furthermore, where considered appropriate,reference labels have been repeated among the figures to indicatecorresponding or analogous elements.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment or embodiments disclosed, but that the presentinvention encompasses all embodiments falling within the scope of theappended claims.

What is claimed is:
 1. A power tool system, comprising: a twenty volt(20V) power tool comprising a handle and a battery compartment in thehandle; and a battery pack comprising a housing and a plurality ofbattery cells, the housing comprising a base portion and a post portionthat extends from the base portion, the plurality of battery cellsarranged in the base portion and the post portion of the housing suchthat at least 50% of at least two battery cells reside within the postportion of the battery pack; wherein the base portion of the housingextends further from the post portion in a first direction perpendicularto a longitudinal axis of the post portion than in a second directionopposite to the first direction; wherein the handle is configured tooperably receive the post portion in at least two orientations so as topermit at least two orientations of the base portion with respect to thepower tool; wherein the plurality of battery cells includes at leastfive battery cells that each provide a nominal 4 volts; wherein thebattery compartment is configured to receive the post portion of thebattery pack and operably couple the plurality of battery cells to thepower tool via the received post portion; and wherein at least 50% ofthe at least two battery cells reside within the handle of the powertool when the battery pack is operably coupled to the power tool.
 2. Thepower tool system of claim 1, wherein at least 80% of the at least twobattery cells reside within the handle of the power tool when thebattery pack is operably coupled to the power tool.
 3. The power toolsystem of claim 1, wherein at least 100% of the at least two batterycells reside within the handle of the power tool when the battery packis operably coupled to the power tool.
 4. The power tool system of claim1, wherein each battery cell of the plurality of battery cells is acylindrical lithium-ion battery cell having a diameter of 14millimeters.
 5. The power tool system of claim 1, wherein each batterycell of the plurality of battery cells is a cylindrical lithium-ionbattery cell having a diameter of 18 millimeters.
 6. The power toolsystem of claim 1, wherein each battery cell of the plurality of batterycells is a cylindrical lithium-ion battery cell having a diameter of 20millimeters.
 7. The power tool system of claim 1, wherein each batterycell of the plurality is a cylindrical lithium-ion battery cell.
 8. Thepower tool system of claim 7, wherein the plurality of battery cellsincludes ten lithium-ion battery cells connected to deliver a nominal 20volts.
 9. The power tool system of claim 1, wherein: the plurality ofbattery cells comprises a plurality of first battery cells arranged inthe base portion of the housing; each first battery cell comprises alongitudinal axis that is parallel to longitudinal axes of other firstbattery cells of the plurality of first battery cells; and each of theat least two battery cells comprises a longitudinal axis that is notparallel to the longitudinal axes of the plurality of first batterycells.
 10. The power tool system of claim 9, wherein each of the atleast two battery cells has an end that extends into a gap between twobattery cells of the plurality of first battery cells.
 11. The powertool system of claim 10, wherein: the plurality of battery cellscomprises a second battery cell arranged in the base portion of thehousing; and the second battery cell comprises a longitudinal axis thatis perpendicular to longitudinal axes of the plurality of first batterycells.
 12. A battery pack for a twenty volt (20V) power tool comprisinga battery compartment, the battery pack comprising: a housing comprisinga base portion and a post portion; and at least five battery cells thateach provide a nominal 4 volts; wherein the at least five battery cellsinclude a plurality of first battery cells and a plurality of secondbattery cells; wherein the plurality of first battery cells are arrangedin the base portion of the housing; wherein the plurality of secondbattery cells are arranged in the post portion of the housing; whereinthe post portion is configured to enter the battery compartment in atleast two orientations and operably couple the at least five batterycells to the power tool via the battery compartment so as to permit atleast two orientations of the base portion with respect to the powertool; wherein the post portion is further configured to position atleast 50% of at least two second battery cells of the plurality ofsecond battery cells within the battery compartment of the power toolwhen the battery pack is operably coupled to the power tool; wherein thebase portion of the housing extends further from the post portion in afirst direction perpendicular to a longitudinal axis of the post portionthan in a second direction opposite to the first direction; and whereinthe base portion is configured to position the plurality of firstbattery cells outside the battery compartment of the power tool.
 13. Thebattery pack of claim 12, wherein the post portion is further configuredto position at least 80% of the at least two second battery cells withinthe battery compartment of the power tool when the battery pack isoperably coupled to the power tool.
 14. The battery pack of claim 12,wherein the post portion is further configured to position at least 100%of the at least two second battery cells within the battery compartmentof the power tool when the battery pack is operably coupled to the powertool.
 15. The battery pack of claim 12, wherein each first battery celland second battery cell is a cylindrical lithium-ion battery cell havinga diameter of 14 millimeters.
 16. The battery pack of claim 12, whereineach first battery cell and second battery cell is a cylindricallithium-ion battery cell having a diameter of 18 millimeters.
 17. Thebattery pack of claim 12, wherein each first battery cell and secondbattery cell is a cylindrical lithium-ion battery cell having a diameterof 20 millimeters.
 18. The battery pack of claim 12, wherein theplurality of first battery cells and the plurality of second batterycells collectively include ten lithium-ion battery cells connected todeliver a nominal 20 volts.
 19. The battery pack of claim 12, wherein:each first battery cell comprises a longitudinal axis that is parallelto longitudinal axes of other first battery cells of the plurality offirst battery cells; each second battery cell comprises a longitudinalaxis that is parallel to longitudinal axes of other second battery cellsof the plurality of second battery cells; and the longitudinal axes ofthe plurality of first battery cells are not parallel to thelongitudinal axes of the plurality of second battery cells.